I have posted the floowing message at the SD mailing list and replicate it here.
I join too the two little models illustrating the mail.
Hi everybody
I have always wondered why the SD profession does not apply to its own case the method it advocates.
There is a saying in French :
‘C’est toujours le chausseur qui est le plus mal chaussé.’
Translation : A shoemaker is rarely well-shod.
I have made two little models that test one of the hypotheses that could explain the slow
growth of the field in the business world.
I believe that the growth is partially driven by the percentage of people having tried the method and being satisfied with it.
To have a high percentage it is preferable to discard the clients that may be interested but
for many reasons have a low probability to become ever satisfied (called in the model false potential) and privilege the clients with high probability (called in the model true potential).
There are two models: the first one starts for instance to-day and is called growth lasts 50 years and the second starts fifty years ago and lasts 100 years and is called growth2.
In both models the policy variable is in green and is called ‘policy about false potential’ and can range from 1 that accepts all candidates with a low probability to be satisfied to 0 that accepts no candidates.
They are posted at the Vensim forum.
http://www.ventanasystems.co.uk/forum/
system dynamics discussion.
If the models are right it confirms the idea that promoting a policy that discard low probability satisfaction customers, generates a slow growth the first years and a stronger growth later on.
I think that the SDS should try to build the same kind of model that would have two objectives.
One obvious: finding better policies to encourage the method and the second:
By making the modelling public, show how the method can be applied and gives concrete results. The modelling process could be made public and the participants of the mailing list or/and the SD members could openly participate and criticize the modelling process.
I built the two models in about an hour this morning and do not pretend to have made a
serious work! It is just an example.
The model can too describe the growth of the different sectors of application (ecology, economy, etc…)
Regards.
Jean-Jacques Laublé. Eurli Allocar
Strasbourg. France.
why not build a model of the growth of the field
why not build a model of the growth of the field
- Attachments
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- growth.zip
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From an academic's perspective, the growth of SD is measured in part by impact factor of the SDR. We view the field as under growth phase if the impact factor tends to increase yearly, meaning more academics use SD knowledge published in the field journal.
Why do we expect a greater number of SD user, rather than a greater understanding of the discipline among individuals? Number of SD practitioners and system dynamics are very different objects indeed. Should we consider the growth of the field itself or the growth of the field members? To me, the level of SD knowledge (theory), e.g., measured by number of good textbooks, is much more important and worth modeling than the level of SD followers.
Good SD followers, how many they are, will die due to aging, and knowledge in their heads will lost with them. By contrast, good SD textbooks, even one to ten books, will be immortal and represent the field in a much longer time horizon.
Scripture is more important than temples and followers.
Why do we expect a greater number of SD user, rather than a greater understanding of the discipline among individuals? Number of SD practitioners and system dynamics are very different objects indeed. Should we consider the growth of the field itself or the growth of the field members? To me, the level of SD knowledge (theory), e.g., measured by number of good textbooks, is much more important and worth modeling than the level of SD followers.
Good SD followers, how many they are, will die due to aging, and knowledge in their heads will lost with them. By contrast, good SD textbooks, even one to ten books, will be immortal and represent the field in a much longer time horizon.
Scripture is more important than temples and followers.
An answer to JJ's question, "Why does SD profession not apply to its own case the method it advocates?" is this: Because the problem is too simple and not worth addressing. I regard SD as growing, and have no problem with the field dynamics.
I would keep SD for addressing other more important problem. In Chinese saying, "Don't apply a cow killing knife to a chicken".
JJ, your desired behavior is indeed the growth of understanding of SD, you tried to model the number of SD followers, right?
I would keep SD for addressing other more important problem. In Chinese saying, "Don't apply a cow killing knife to a chicken".
JJ, your desired behavior is indeed the growth of understanding of SD, you tried to model the number of SD followers, right?
SD modelling
Hi
I was asking why the SD profeesion did not try to apply a method that it advocates to its own case?
There may be many reasons.
The opportunity of modelling can be justified by the fact that many SD'ers (see past postings) wonder why SD is not more used in particular in the business work but in politics too.
Regards.
JJ
I was asking why the SD profeesion did not try to apply a method that it advocates to its own case?
There may be many reasons.
The opportunity of modelling can be justified by the fact that many SD'ers (see past postings) wonder why SD is not more used in particular in the business work but in politics too.
Regards.
JJ
System Dynamics - a chance in a changing global world
Hello Monte,
hello Jean-Jacques,
the point is -from my point of view- not so much how many persons are flowing into the stock of SD knowers rather than how much SD knowledge is flowing into companies, organizations and accumulate there.
To my present understanding and personal experience there is still a too strong connection between the SD knowers in a company and the SD knowledge right there. As soon as the person is leaving its position or the company the knowledge is completely lost.
The question is, why despite the awesome workshops at MIT (attended this myself) or other ones covering the questions of System Dynamics practical use there are still very few people who know the field.
Just a couple of minutes ago I chatted with a friend on the use of modelling for explaining why Lean Thinking (Toyota's way of staying ahead of competition) is so difficult to implement in existing companies. The reason for doing a conversation with down-under is that there is practicably nobody around to discuss matters (connectiing Lean and System Dynamics).
What are the underlying reasons for that? A model building with diverse input, points of views and personal experience is a rather good idea and not just a tiny problem.
This could have spill-over (or so-called uninticipated side effects;)) on other fields as well for the better:)
Best regards at a rather late time but I thought my thoughts had to be written down.
Ralf
hello Jean-Jacques,
the point is -from my point of view- not so much how many persons are flowing into the stock of SD knowers rather than how much SD knowledge is flowing into companies, organizations and accumulate there.
To my present understanding and personal experience there is still a too strong connection between the SD knowers in a company and the SD knowledge right there. As soon as the person is leaving its position or the company the knowledge is completely lost.
The question is, why despite the awesome workshops at MIT (attended this myself) or other ones covering the questions of System Dynamics practical use there are still very few people who know the field.
Just a couple of minutes ago I chatted with a friend on the use of modelling for explaining why Lean Thinking (Toyota's way of staying ahead of competition) is so difficult to implement in existing companies. The reason for doing a conversation with down-under is that there is practicably nobody around to discuss matters (connectiing Lean and System Dynamics).
What are the underlying reasons for that? A model building with diverse input, points of views and personal experience is a rather good idea and not just a tiny problem.
This could have spill-over (or so-called uninticipated side effects;)) on other fields as well for the better:)
Best regards at a rather late time but I thought my thoughts had to be written down.
Ralf
Ralf Lippold
-
martin.schaffernicht
- Junior Member
- Posts: 7
- Joined: Sun Sep 09, 2007 9:42 pm
Designing the professional future-designer’s future
I may be forgiven for borrowing the “designing the future” word; some of the recent discussion about the death, future and growth of system dynamics, about the “profession” and about the design o better organizations seem to move around a common theme.
The “system dynamicist” has been compared with the designer of an aircraft (whereas the typical manager is the pilot and it is thus logical to ask: then who designs the “organization”)? This is a powerful analogy, of which I’d like to discuss some possible issues. (A little qualitative model is attached to this message in the forum at
http://www.ventanasystems.co.uk/forum/
It is full of oversimplifications, has no mention of the time structure and no equations and awaits your comments and suggestions.)
1. From many discussions on this list, I have the impression that many dynamicists see themselves as “solvers of (our clients’) problems”. This sounds more like a “medical doctor” whose work is diagnosing and prescribing a cure (and sometimes an autopsy). True: as long as there exist problems, and as long as concerned people ask you to do so (sometimes even without this), it is important to help solving them. When doing so, you are trying to augment the outflow of the “problems” stock. If we take an example like global climate, this is evidently very important.
But then, it is not the dynamicist whose actions created the problem, and those whose actions created the problem are not dynamicists. And usually (adult) people do not like to be told “you should change what you are doing/believeing”. How may times, the guy who brings the bad new is punished for the news? So there is some in-built limitation in the idea of the dynamicist as solver of problems others create, and as long as we think of two separate agents (a “patient” to create the problem and a “physician” to solve it), this will be hard to overcome.
But it is not all there is.
2. There is another stock that we may call “potential problems”; this is a resource that (prepared) people can draw upon to avoid problems and thus reduce the inflow into “problems”: having more people acting in ways that do not create problems in the first place. But this is not “solving people’s problems”, rather “teach them how to avoid problems”, a bit like a medical doctor who gives advice and teaching to “(not yet sick) patients”. However, how many people go to their physician to say “doctor, help me not to fall sick”? Rather, the dynamicist as “avoider of problems other people could create” will be a sort of “devil’s advocate” (just think of “limits to growth”): not a very easy strategy to catch “users”.
So the analogy of the “pilot” as decision-making agent (manager, mayor ...) who may increase the “problems” inflow and the dynamicist as “designer/engineer” who decreases the inflow does not overcome the division into two different agents. The barrier mentioned above will not go away as long as the “pilot” has no personal access to the “potential problems” stock. Well, aircraft pilots are not aircraft designers, but they study a lot of things about aircraft and weather (and so on) and permanently confront themselves with problem-avoiding training in the simulator. However, these simulation models “model the SYSTEM”, not the PROBLEM; since system dynamics is really about problems, I’m not sure if the analogy holds.
3. The social or “human activity” systems we are concerned with are different from airplanes or chemical plants in one important aspect: they are made up from conscious, interest-laden, emotion-driven and intelligent components – “people”. Thinking of such systems like an airplane, made up from many sophisticated components may be replaced by thinking of them as swarms of little airplanes (each with its own pilot). The swarm will look organized as long as each of the planes stays synchronized; but even if there is a formal “leader”, each pilot is a “person”.
Now if each of these pilots has been trained in the “problem space”, he will be able to draw upon the “potential problems” stock. One swarm’s pilots can even organize a briefing and review the synchronization rules. And so they will avoid problems during flight (anyway they would not be able to stop action and call in a “physician” to solve their problem). You would not design this organization in too direct a way, rather set up the fewest necessary restrictions and let each pilot be “intelligent”.
4. The designer – pilot analogy should not make us think that system dynamics shall be a profession limited to the “design” activity. Since the social world is mainly made up of pilots, patients and the like, the “potential problems” stock (one of the two treasures of system dynamics) has to be made available to them. This means that the dynamicist community has to do a lot of education, producing all kinds of artifacts to interact with (books, comics, movies, simulation games...), for the general public, for children, for educators and for the other professions (the “pilots”). By using these artifacts, people will change their mental models (more than by being told to do so). So the basic insights and ideas of system dynamics would spread over the non-specialist population – slowly but steadily, and some day one could say “we are all dynamicists now (a bit)”.
Then the “everyday system dynamicist” should be expected to be someone who causes fewer problems (like a French shoemaker with nice shoes). Looking at things and seeing stocks that can be increased and decreased, being sensitive to feedback loops, asking yourself about the time horizon, about delays, about things you do not know or cannot be sure about, this can become part of your way of living, even if you are not specially skilled at simulation model validating.
5. But who governs the inflow into the “potential problems” stock? Well, this is the other task of the “professional system dynamicist”. There is a “general constructs” (like the typical “S”-shaped growth and its generic feedback-loop structure) stock and a “modeling techniques” stock, that the professional dynamicist would have to nourish. These two stocks are the second “treasure” of system dynamics; they may be less accessed by the “everyday system dynamicist”, but they are the resources for nourishing the “potential problems” stock. (I should stress that the “everyday dynamicist” also needs a minimum access to the other two treasures in order to allow him to think on his own.)
6. Also, the “professional dynamicist” will work as “problem avoider” and “problem solver”, aiding others (with his special “modeling techniques” treasure); thus the “problems” outflow will also be the “solved problems” stock’s inflow, and new material will nourish the “general constructs” stock.
7. The “potential problems” stock would really be sub-indexed, since these refer to rather specific areas, like “organizations”, “cities”, “health”, “education” and others. So the “professional dynamicist” would also be in charge of “family tree” inquiry, synthesizing general constructs and specifying generic potential problems.
8. So it seems to me that system dynamics (have you sometimes wondered if it should be called “problem dynamics”?) is one name given to two professional areas: those who feel the call for system dynamics have to develop the treasures and share at least one of them: the “potential problems”, and also sometimes to solve other people’s problems. I believe the first part of it is doing quite well: “modeling technique” is growing, and so is “general constructs”. I believe the “physician” mode is quite developed, too; and if it is the case that it is not growing as fast as it could, then this is the consequence of not having developed a sufficient stock of “everyday dynamicists” able to exploit the “potential problems” stock (and to constitute the growing demand for “professional dynamicists”).
However, I feel like there most of the “big fishes” in system dynamics concentrate on the things described under points 5 and 6 (above). This is what you can publish in journals and this is what allows to do consulting. I have wondered for some time now why the founder of the field appears to be the only one who has gone to point 4, helping to grow the “everyday dynamicist” stock. Yes, there is an education SIG, yes there is wonderful material (at least in English language), yes there are quite a few people working in “educational stuff”. But how many universities have pedagogical units with full professors who actively research and develop system dynamics as a part of material developed and teachers trained?
If the little model with “generic constructs”, “modeling technique”, “potential problems”, “problems”, “solved problems”, professional dynamicistes” and “everyday dynamisists” is conceptually valid, then the community of system dynamics should search for more people to work at growing the inflow to “everyday dynamicists” (and lessen the “problems” inflow).
I would not like the practitioners amongst you to feel bothered by this: it is not necessary to have fewer of you. But I believe it is necessary to have more highly visible system dynamics “believers” interested in developing the inflow into “everyday dynamicists”.
Shouldn’t this be part of system dynamic’s growth strategy?
Best greetings,
Martin Schaffernicht
The “system dynamicist” has been compared with the designer of an aircraft (whereas the typical manager is the pilot and it is thus logical to ask: then who designs the “organization”)? This is a powerful analogy, of which I’d like to discuss some possible issues. (A little qualitative model is attached to this message in the forum at
http://www.ventanasystems.co.uk/forum/
It is full of oversimplifications, has no mention of the time structure and no equations and awaits your comments and suggestions.)
1. From many discussions on this list, I have the impression that many dynamicists see themselves as “solvers of (our clients’) problems”. This sounds more like a “medical doctor” whose work is diagnosing and prescribing a cure (and sometimes an autopsy). True: as long as there exist problems, and as long as concerned people ask you to do so (sometimes even without this), it is important to help solving them. When doing so, you are trying to augment the outflow of the “problems” stock. If we take an example like global climate, this is evidently very important.
But then, it is not the dynamicist whose actions created the problem, and those whose actions created the problem are not dynamicists. And usually (adult) people do not like to be told “you should change what you are doing/believeing”. How may times, the guy who brings the bad new is punished for the news? So there is some in-built limitation in the idea of the dynamicist as solver of problems others create, and as long as we think of two separate agents (a “patient” to create the problem and a “physician” to solve it), this will be hard to overcome.
But it is not all there is.
2. There is another stock that we may call “potential problems”; this is a resource that (prepared) people can draw upon to avoid problems and thus reduce the inflow into “problems”: having more people acting in ways that do not create problems in the first place. But this is not “solving people’s problems”, rather “teach them how to avoid problems”, a bit like a medical doctor who gives advice and teaching to “(not yet sick) patients”. However, how many people go to their physician to say “doctor, help me not to fall sick”? Rather, the dynamicist as “avoider of problems other people could create” will be a sort of “devil’s advocate” (just think of “limits to growth”): not a very easy strategy to catch “users”.
So the analogy of the “pilot” as decision-making agent (manager, mayor ...) who may increase the “problems” inflow and the dynamicist as “designer/engineer” who decreases the inflow does not overcome the division into two different agents. The barrier mentioned above will not go away as long as the “pilot” has no personal access to the “potential problems” stock. Well, aircraft pilots are not aircraft designers, but they study a lot of things about aircraft and weather (and so on) and permanently confront themselves with problem-avoiding training in the simulator. However, these simulation models “model the SYSTEM”, not the PROBLEM; since system dynamics is really about problems, I’m not sure if the analogy holds.
3. The social or “human activity” systems we are concerned with are different from airplanes or chemical plants in one important aspect: they are made up from conscious, interest-laden, emotion-driven and intelligent components – “people”. Thinking of such systems like an airplane, made up from many sophisticated components may be replaced by thinking of them as swarms of little airplanes (each with its own pilot). The swarm will look organized as long as each of the planes stays synchronized; but even if there is a formal “leader”, each pilot is a “person”.
Now if each of these pilots has been trained in the “problem space”, he will be able to draw upon the “potential problems” stock. One swarm’s pilots can even organize a briefing and review the synchronization rules. And so they will avoid problems during flight (anyway they would not be able to stop action and call in a “physician” to solve their problem). You would not design this organization in too direct a way, rather set up the fewest necessary restrictions and let each pilot be “intelligent”.
4. The designer – pilot analogy should not make us think that system dynamics shall be a profession limited to the “design” activity. Since the social world is mainly made up of pilots, patients and the like, the “potential problems” stock (one of the two treasures of system dynamics) has to be made available to them. This means that the dynamicist community has to do a lot of education, producing all kinds of artifacts to interact with (books, comics, movies, simulation games...), for the general public, for children, for educators and for the other professions (the “pilots”). By using these artifacts, people will change their mental models (more than by being told to do so). So the basic insights and ideas of system dynamics would spread over the non-specialist population – slowly but steadily, and some day one could say “we are all dynamicists now (a bit)”.
Then the “everyday system dynamicist” should be expected to be someone who causes fewer problems (like a French shoemaker with nice shoes). Looking at things and seeing stocks that can be increased and decreased, being sensitive to feedback loops, asking yourself about the time horizon, about delays, about things you do not know or cannot be sure about, this can become part of your way of living, even if you are not specially skilled at simulation model validating.
5. But who governs the inflow into the “potential problems” stock? Well, this is the other task of the “professional system dynamicist”. There is a “general constructs” (like the typical “S”-shaped growth and its generic feedback-loop structure) stock and a “modeling techniques” stock, that the professional dynamicist would have to nourish. These two stocks are the second “treasure” of system dynamics; they may be less accessed by the “everyday system dynamicist”, but they are the resources for nourishing the “potential problems” stock. (I should stress that the “everyday dynamicist” also needs a minimum access to the other two treasures in order to allow him to think on his own.)
6. Also, the “professional dynamicist” will work as “problem avoider” and “problem solver”, aiding others (with his special “modeling techniques” treasure); thus the “problems” outflow will also be the “solved problems” stock’s inflow, and new material will nourish the “general constructs” stock.
7. The “potential problems” stock would really be sub-indexed, since these refer to rather specific areas, like “organizations”, “cities”, “health”, “education” and others. So the “professional dynamicist” would also be in charge of “family tree” inquiry, synthesizing general constructs and specifying generic potential problems.
8. So it seems to me that system dynamics (have you sometimes wondered if it should be called “problem dynamics”?) is one name given to two professional areas: those who feel the call for system dynamics have to develop the treasures and share at least one of them: the “potential problems”, and also sometimes to solve other people’s problems. I believe the first part of it is doing quite well: “modeling technique” is growing, and so is “general constructs”. I believe the “physician” mode is quite developed, too; and if it is the case that it is not growing as fast as it could, then this is the consequence of not having developed a sufficient stock of “everyday dynamicists” able to exploit the “potential problems” stock (and to constitute the growing demand for “professional dynamicists”).
However, I feel like there most of the “big fishes” in system dynamics concentrate on the things described under points 5 and 6 (above). This is what you can publish in journals and this is what allows to do consulting. I have wondered for some time now why the founder of the field appears to be the only one who has gone to point 4, helping to grow the “everyday dynamicist” stock. Yes, there is an education SIG, yes there is wonderful material (at least in English language), yes there are quite a few people working in “educational stuff”. But how many universities have pedagogical units with full professors who actively research and develop system dynamics as a part of material developed and teachers trained?
If the little model with “generic constructs”, “modeling technique”, “potential problems”, “problems”, “solved problems”, professional dynamicistes” and “everyday dynamisists” is conceptually valid, then the community of system dynamics should search for more people to work at growing the inflow to “everyday dynamicists” (and lessen the “problems” inflow).
I would not like the practitioners amongst you to feel bothered by this: it is not necessary to have fewer of you. But I believe it is necessary to have more highly visible system dynamics “believers” interested in developing the inflow into “everyday dynamicists”.
Shouldn’t this be part of system dynamic’s growth strategy?
Best greetings,
Martin Schaffernicht
growth of SD
Hi Ralf
About your question about why SD is nor more used, I think that the answer will vary with every situation and one can always speculate about the multiple reasons.
I do not have to speculate about my case and I know by experience the difficulties that I met.
These difficulties may not be the difficulties that will meet other persons in other situation but I think that they must be very common.
Like any experience it is difficult to share and the answer to your question is: make your own models and then one can discuss about something concrete and you will get some experience.
If I want to summarize my own experience until now:
I think that a model to be useful must have references on the past and describe a method that has been used with tools that have been used too.
There must be a starting point.
From that point it must propose slight changes that may help the system to work better and one must try these changes concretely to verify that the hypothesis is right.
I speak of slight changes, because if you want to change to many things at the same time, you will build a very complex model and the many changes proposed have a great probability to change the reality to a point where your model is no more valid.
A second point; in a model the context of the problem should be included in the model and in particular the people that will have to implement the changes and the people that have the power to implement it.
If the policy change is small the influence of that context will be small too and will be easy to include in the model.
To resume, if the policy is relatively simple to apply, the risk of side effects from the client is small.
So for me a good SD model relies on a verified past and proposes the smallest policy changes that have the maximum effect.
SD should try to respect the Pareto laws that are rarely respected when you see the models
In the SD literature.
Once that the change has been realized and the results verified one can then reiterate the process with more confidence because of the first successful result.
This method is not specific to SD but can be applied to any modelling process.
Another point from my experience is:
It is not because you use a complex tool that you get automatically a good result.
If the tool is not adapted or if you cannot master the tool due to its complexity you increase
the chances to fail.
Every time I decide to do something I ask myself: is is possible to make it simpler and what shall I really loose and am I really sure to loose anything by doing it?
For me making things simple have always an advantage, making them more complicate have always a drawback from the added complexity and it is difficult to be sure that there is an added value generated by the added complexity.
Regards.
JJ
About your question about why SD is nor more used, I think that the answer will vary with every situation and one can always speculate about the multiple reasons.
I do not have to speculate about my case and I know by experience the difficulties that I met.
These difficulties may not be the difficulties that will meet other persons in other situation but I think that they must be very common.
Like any experience it is difficult to share and the answer to your question is: make your own models and then one can discuss about something concrete and you will get some experience.
If I want to summarize my own experience until now:
I think that a model to be useful must have references on the past and describe a method that has been used with tools that have been used too.
There must be a starting point.
From that point it must propose slight changes that may help the system to work better and one must try these changes concretely to verify that the hypothesis is right.
I speak of slight changes, because if you want to change to many things at the same time, you will build a very complex model and the many changes proposed have a great probability to change the reality to a point where your model is no more valid.
A second point; in a model the context of the problem should be included in the model and in particular the people that will have to implement the changes and the people that have the power to implement it.
If the policy change is small the influence of that context will be small too and will be easy to include in the model.
To resume, if the policy is relatively simple to apply, the risk of side effects from the client is small.
So for me a good SD model relies on a verified past and proposes the smallest policy changes that have the maximum effect.
SD should try to respect the Pareto laws that are rarely respected when you see the models
In the SD literature.
Once that the change has been realized and the results verified one can then reiterate the process with more confidence because of the first successful result.
This method is not specific to SD but can be applied to any modelling process.
Another point from my experience is:
It is not because you use a complex tool that you get automatically a good result.
If the tool is not adapted or if you cannot master the tool due to its complexity you increase
the chances to fail.
Every time I decide to do something I ask myself: is is possible to make it simpler and what shall I really loose and am I really sure to loose anything by doing it?
For me making things simple have always an advantage, making them more complicate have always a drawback from the added complexity and it is difficult to be sure that there is an added value generated by the added complexity.
Regards.
JJ
-
martin.schaffernicht
- Junior Member
- Posts: 7
- Joined: Sun Sep 09, 2007 9:42 pm
attached file
Can't read the attached file.
What format is .itm?
Regards.
JJ
What format is .itm?
Regards.
JJ
Growth of the field
I have understood.
The file is an Ithink file!
Regards.
JJ
The file is an Ithink file!
Regards.
JJ
-
martin.schaffernicht
- Junior Member
- Posts: 7
- Joined: Sun Sep 09, 2007 9:42 pm
growth of the field
Hi
One can make many remarks about that diagram.
first.
The generic structure, quality of modelling technique, professional dynamicists have an effect on what you name conversion speed, which to my opinion has an effect on the
new potential problems.
Ok. but why does the generic structures have a second effect on the same new potential problems?
You suppose that only everyday dynamicists discover the problems, but professional dynamicsts should do it too?
One can make many remarks about that diagram.
first.
The generic structure, quality of modelling technique, professional dynamicists have an effect on what you name conversion speed, which to my opinion has an effect on the
new potential problems.
Ok. but why does the generic structures have a second effect on the same new potential problems?
You suppose that only everyday dynamicists discover the problems, but professional dynamicsts should do it too?
another remark;
There should be an output rate to the potential problems that can eventually be solved by other techniques or just disappear with the time.
A business may have a problem, but the problem will disappear with the business.
Sale with the problems that are supposed to be all solved.
And what about the problem discovered, and being not addressed sufficiently quickly, is olved by another method, or problems that are not solved correctly with SD?
One can too make other remarks.
But the problem with such a diargram is first to prove its validity, because one can build the same king of diargramm but with a very different strucutre.
And the second point is to valuate the influences, not to mention the valuation of the intitial stocks.
To validate such a model, one should have an idea of the number of models made each year
and the number of dynamicists and be able to detect the professional among amateurs.
And what is a problem?
Is a problem studied in an University and never applied a real problem?
Regards.
JJ
There should be an output rate to the potential problems that can eventually be solved by other techniques or just disappear with the time.
A business may have a problem, but the problem will disappear with the business.
Sale with the problems that are supposed to be all solved.
And what about the problem discovered, and being not addressed sufficiently quickly, is olved by another method, or problems that are not solved correctly with SD?
One can too make other remarks.
But the problem with such a diargram is first to prove its validity, because one can build the same king of diargramm but with a very different strucutre.
And the second point is to valuate the influences, not to mention the valuation of the intitial stocks.
To validate such a model, one should have an idea of the number of models made each year
and the number of dynamicists and be able to detect the professional among amateurs.
And what is a problem?
Is a problem studied in an University and never applied a real problem?
Regards.
JJ
-
martin.schaffernicht
- Junior Member
- Posts: 7
- Joined: Sun Sep 09, 2007 9:42 pm
Dear Jean-Jaques,
thanks for both posts. What first started out as a much smaller diagram to visualize aspects of the mail message I sent, started to grow throught he interaction with Stefan Groesser. I think we will go on trying to convert the diagram into a "real" model. So the questions you asked will be taken into account.
I think you are right in that there are outflows missing and also in that it is not reasonable to assume that the discovery of new problems depends solely on "everyday dynamicists" (those who would call in "professional dynamicists").
I'll shortly post a revised version of the diagram,
Martin
thanks for both posts. What first started out as a much smaller diagram to visualize aspects of the mail message I sent, started to grow throught he interaction with Stefan Groesser. I think we will go on trying to convert the diagram into a "real" model. So the questions you asked will be taken into account.
I think you are right in that there are outflows missing and also in that it is not reasonable to assume that the discovery of new problems depends solely on "everyday dynamicists" (those who would call in "professional dynamicists").
I'll shortly post a revised version of the diagram,
Martin
SD modelling
Hi Martin
I wonder how you will be able to make your model real, if you have no realty to compare it to.
To my opinion prior to making a model, one should first define the data we need and try to get a minimum of information about the realisations of these data in the past.
Otherwise the model however clever it is, will always be a speculation with no
demonstrable credibility.
One can imagine building a model starting from nothing but one must have some credible
information to put into it.
Can you tell me one information from your model that is even slightly correct (within a
medium confidence interval and a reasonable probability)?
I do not want to be discouraging but it is better to face the reality and try to cope with it even if it is not encouraging than to build a very nice mathematical model that only models your
beliefs.
But I appreciate greatly the attempt to build a model openly, in contrast with the habit to talk about SD as it is done in the SD mailing list without ever doing any SD modelling.
Regards.
Jean-Jacques Laublé alias JJ on the Vensim Forum.
I wonder how you will be able to make your model real, if you have no realty to compare it to.
To my opinion prior to making a model, one should first define the data we need and try to get a minimum of information about the realisations of these data in the past.
Otherwise the model however clever it is, will always be a speculation with no
demonstrable credibility.
One can imagine building a model starting from nothing but one must have some credible
information to put into it.
Can you tell me one information from your model that is even slightly correct (within a
medium confidence interval and a reasonable probability)?
I do not want to be discouraging but it is better to face the reality and try to cope with it even if it is not encouraging than to build a very nice mathematical model that only models your
beliefs.
But I appreciate greatly the attempt to build a model openly, in contrast with the habit to talk about SD as it is done in the SD mailing list without ever doing any SD modelling.
Regards.
Jean-Jacques Laublé alias JJ on the Vensim Forum.
Validation is crucial, and is a modeler's duty. It is a good idea to re-define each of the components and relationships in your model; you will find some incorrect parts and may need to omit them and include others. Forrester and Senge (1980)'s tests are capable of improving your model.
If you have time, a better idea is to spend a year or two for gathering information on your dynamic problem. If you find information insufficient, you may adjust the purpose of your model, by asking a new question that can be answered using the available information, and that can serve the purpose equally well. The new question must be sharp--able to remove the complex part of the system from your focus. Developing a highly aggregated model first is a strategy I adopted. Small models are easy to validate, and to be understood by all.
The best idea is to find a small, but important problem. You will have a chance of success.
If you have time, a better idea is to spend a year or two for gathering information on your dynamic problem. If you find information insufficient, you may adjust the purpose of your model, by asking a new question that can be answered using the available information, and that can serve the purpose equally well. The new question must be sharp--able to remove the complex part of the system from your focus. Developing a highly aggregated model first is a strategy I adopted. Small models are easy to validate, and to be understood by all.
The best idea is to find a small, but important problem. You will have a chance of success.
-
martin.schaffernicht
- Junior Member
- Posts: 7
- Joined: Sun Sep 09, 2007 9:42 pm
Dear Jean-Jaques,
thanks for the critical questions in the three posts. I think the apparent dificulty in quantifying the variabels in the "sketch" (diagram) has to do with:
1) units of measure have not been defined;
2) many of these variabels will need quita de deal of "guessing" to attempt quantification.
I think there will be a way to quantify "generic structures" and "possible problems", even though they may look weird. Other ones looke quite speculative to me, at least now. For example, it is not too hard to figure out how many "professional dynamicists" there are: by looking at how many active modelers are running around. (I start to think that "practitioners" should be counted separately from "academics"..) Maybe we could also say that the alumni of the recognized DS-programmes are to be considered "everyday dynamicists"; there may be some additional amount of autodidacts.
I don't know how slow this process will be, since I do not have much time to dedicate to this (and I'm sure that you ans Stefan find yourselves in the same situation).
However, I find it elightening. There has been, is and will be quite an amount of discussion about how "system dynammics" grows (or not). My contribution may not be such relevant a peice, because I'm certainly not a "big fish", but the diagram lets me feel how little of firm knowleddge was in my thoughts, and how speculative they were (though they may be logically coherent). Isn't this the case of much of the discussion in general.
One again, sorry for being slow, but all your comments will be taken into account!
And if anybody else wishes to join, you'd be welcome.
Martin
Martin
thanks for the critical questions in the three posts. I think the apparent dificulty in quantifying the variabels in the "sketch" (diagram) has to do with:
1) units of measure have not been defined;
2) many of these variabels will need quita de deal of "guessing" to attempt quantification.
I think there will be a way to quantify "generic structures" and "possible problems", even though they may look weird. Other ones looke quite speculative to me, at least now. For example, it is not too hard to figure out how many "professional dynamicists" there are: by looking at how many active modelers are running around. (I start to think that "practitioners" should be counted separately from "academics"..) Maybe we could also say that the alumni of the recognized DS-programmes are to be considered "everyday dynamicists"; there may be some additional amount of autodidacts.
I don't know how slow this process will be, since I do not have much time to dedicate to this (and I'm sure that you ans Stefan find yourselves in the same situation).
However, I find it elightening. There has been, is and will be quite an amount of discussion about how "system dynammics" grows (or not). My contribution may not be such relevant a peice, because I'm certainly not a "big fish", but the diagram lets me feel how little of firm knowleddge was in my thoughts, and how speculative they were (though they may be logically coherent). Isn't this the case of much of the discussion in general.
One again, sorry for being slow, but all your comments will be taken into account!
And if anybody else wishes to join, you'd be welcome.
Martin
Martin
Sd Growth
Hi Martin
It took some time to answer your message, but I had caught a cold.
About the model you are trying to build, you could look at the Vensim model in the documentation. It models the growth of SD.
It can be a good starting point too.
But what is the purpose of the model and what can it be
useful to?
Thinking about the objective may be useful for the modelling.
Maybe that starting first with the simpler model that one can imagine about the problem and then adding new material step by step only if there are enough justification for it might be a good strategy of development too.
But one must first define a purpose for the model.
The idea is that everytime that one adds something new to the model, to ask the question: adding this is something valuable relative to the objective of the model and what is clearly the value?
This seems to me constructive and can lead to a group discussion.
I wanted to start with a simplistic model, like a stock with
an input and an ouput rate, that is the more close to the problem but having no clear objective it is impossible
Regards.
JJ
[Edited on 20-9-2007 by LAUJJL]
[Edited on 20-9-2007 by LAUJJL]
It took some time to answer your message, but I had caught a cold.
About the model you are trying to build, you could look at the Vensim model in the documentation. It models the growth of SD.
It can be a good starting point too.
But what is the purpose of the model and what can it be
useful to?
Thinking about the objective may be useful for the modelling.
Maybe that starting first with the simpler model that one can imagine about the problem and then adding new material step by step only if there are enough justification for it might be a good strategy of development too.
But one must first define a purpose for the model.
The idea is that everytime that one adds something new to the model, to ask the question: adding this is something valuable relative to the objective of the model and what is clearly the value?
This seems to me constructive and can lead to a group discussion.
I wanted to start with a simplistic model, like a stock with
an input and an ouput rate, that is the more close to the problem but having no clear objective it is impossible
Regards.
JJ
[Edited on 20-9-2007 by LAUJJL]
[Edited on 20-9-2007 by LAUJJL]
-
martin.schaffernicht
- Junior Member
- Posts: 7
- Joined: Sun Sep 09, 2007 9:42 pm
Hi Jean-Jaques,
sorry, I'm off on a vacation for one week, so I did not visit the forum regularly!
The starting-point for what now starts to look like a modeling effort was my uneasy "feeling" about what the SD-commuinty undertakes, the worries about slow growth, together with professor Forrester's message about the next 50 years of system dynamics. I somehow think that if most of the dynamicists concentrate on solving (others') problems, and if this is reinforced by the incentive structure (which may different for consultants and for academics), then SD will grow slowly. Jay Forrester's orientation towards education seems so straightforward, but I find that (seen at a global scale) the SD community has not "bought in".
Then I tried to write it up as a post to the SD-list and in the process it turned out to be expressable in terms of stocks and flows (I did not planit this way).
So up to a certain point, I'm only trying to obtain clarity about what I'm thinking, specifically the relationship between the idea of system dynamics as a means to make thew world a "less worse" place, of that avoiding problems may be preferred over solving them and of the role of education.
I think the central idea is "how to help having more people who avoid creating new problems?" The "problem" is that too few children come into contact with SD and thus there will not be enough "everyday dynamicists". Then the modeling work shall help to answer the question "how to strengthen the immersion of SD into formal education?" and "how much is it reasonable to extect?".
This is clearly too big a question for one guy like me to answer; however, this is precisely what makes me adhere to SD and advocate it, that is what makes me work hard with my students (I work in a university).
Stefan Grösser felt that he wanted to go through this together with me, and we both think that the forum may help other interested members to join in.
I think the firts versins were biased towards the "problem-avoiding" part, and your questions have helped me to focus. The current version includes more details about education, and all the doubts and ideas are documented inside the very model. It is still with "iThink", but I started thinking of moving to Vensim (o everybody can join easily). However, this version is still "iThink", so I attach an image of it's diagram (which does not allow to see the comments, alas; I cannon see how ).
Sorry, the diagram is larger than the previous one. I'm functioning like an "accordeon": sometimes the thing expands, at other times it shrinks. If you look at it, the education sector is more "down-to-earth" and we will try to quantify from here on.
I'm thinking about how to take up the ideas expressed in your Vensim model. It's much simpler, true, but how do I connect with the "education" question?
Of cause you and everybody else are invited to keep being critical, this helps a lot. (I know I'm being slow, but please consider that this is a clandestine activity.)
Looking forward to your next questins and suggestions,
Martin
sorry, I'm off on a vacation for one week, so I did not visit the forum regularly!
The starting-point for what now starts to look like a modeling effort was my uneasy "feeling" about what the SD-commuinty undertakes, the worries about slow growth, together with professor Forrester's message about the next 50 years of system dynamics. I somehow think that if most of the dynamicists concentrate on solving (others') problems, and if this is reinforced by the incentive structure (which may different for consultants and for academics), then SD will grow slowly. Jay Forrester's orientation towards education seems so straightforward, but I find that (seen at a global scale) the SD community has not "bought in".
Then I tried to write it up as a post to the SD-list and in the process it turned out to be expressable in terms of stocks and flows (I did not planit this way).
So up to a certain point, I'm only trying to obtain clarity about what I'm thinking, specifically the relationship between the idea of system dynamics as a means to make thew world a "less worse" place, of that avoiding problems may be preferred over solving them and of the role of education.
I think the central idea is "how to help having more people who avoid creating new problems?" The "problem" is that too few children come into contact with SD and thus there will not be enough "everyday dynamicists". Then the modeling work shall help to answer the question "how to strengthen the immersion of SD into formal education?" and "how much is it reasonable to extect?".
This is clearly too big a question for one guy like me to answer; however, this is precisely what makes me adhere to SD and advocate it, that is what makes me work hard with my students (I work in a university).
Stefan Grösser felt that he wanted to go through this together with me, and we both think that the forum may help other interested members to join in.
I think the firts versins were biased towards the "problem-avoiding" part, and your questions have helped me to focus. The current version includes more details about education, and all the doubts and ideas are documented inside the very model. It is still with "iThink", but I started thinking of moving to Vensim (o everybody can join easily). However, this version is still "iThink", so I attach an image of it's diagram (which does not allow to see the comments, alas; I cannon see how ).
Sorry, the diagram is larger than the previous one. I'm functioning like an "accordeon": sometimes the thing expands, at other times it shrinks. If you look at it, the education sector is more "down-to-earth" and we will try to quantify from here on.
I'm thinking about how to take up the ideas expressed in your Vensim model. It's much simpler, true, but how do I connect with the "education" question?
Of cause you and everybody else are invited to keep being critical, this helps a lot. (I know I'm being slow, but please consider that this is a clandestine activity.)
Looking forward to your next questins and suggestions,
Martin
- Attachments
-
- growth_6.zip
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Sd Growth
Hi Martin
I have a great difficulty of understanding the objective of the model and the purpose behind it.
You are working in an university and are therefore concerned by the educational side of SD.
But if it is only the educational side of SD that you want to promote you must be clear about it and we will work toward this direction.
But we cannot afterwards start working toward another direction unless it is related to the first objective.
If you are not strictly concerned by the educational part of SD, then you are confusing the
problem and the solution. One of the solutions may promote education, but it has still to be demonstrated how and at what extent by the model.
You start by the uneasiness of the Sders, then write about the world getting better, then
"how to strengthen the immersion of SD into formal education?" and "how much is it reasonable to expect?".
Actually, the problem we are trying to solve being not clearly defined, and it takes much more time than that to do it generally, I cannot even express the slightest comment on your model.
I think too that it goes a bit too quickly, but first define the problem clearly.
What you want is maybe clear in your head but it is not written down in clear words so that other people may participate to the effort.
Regards.
JJ
I have a great difficulty of understanding the objective of the model and the purpose behind it.
You are working in an university and are therefore concerned by the educational side of SD.
But if it is only the educational side of SD that you want to promote you must be clear about it and we will work toward this direction.
But we cannot afterwards start working toward another direction unless it is related to the first objective.
If you are not strictly concerned by the educational part of SD, then you are confusing the
problem and the solution. One of the solutions may promote education, but it has still to be demonstrated how and at what extent by the model.
You start by the uneasiness of the Sders, then write about the world getting better, then
"how to strengthen the immersion of SD into formal education?" and "how much is it reasonable to expect?".
Actually, the problem we are trying to solve being not clearly defined, and it takes much more time than that to do it generally, I cannot even express the slightest comment on your model.
I think too that it goes a bit too quickly, but first define the problem clearly.
What you want is maybe clear in your head but it is not written down in clear words so that other people may participate to the effort.
Regards.
JJ
-
martin.schaffernicht
- Junior Member
- Posts: 7
- Joined: Sun Sep 09, 2007 9:42 pm
Dear Jean-Jaques,
you are surely right when you write that my purpose is not clear. It may even be that I should not be engaging in a modelling effort on this: I'm not the "owner" of the hypothetical problem of SD growing slow, and speeding this grow does not depend on decisions I can take.
I've got to reflect a bit and decide if pursuing this idea is a good idea. Maybe I should narrow down the scope to the problem of slow diffusion in the educational system of my country... let me think about it.
Thanks,
Martin
you are surely right when you write that my purpose is not clear. It may even be that I should not be engaging in a modelling effort on this: I'm not the "owner" of the hypothetical problem of SD growing slow, and speeding this grow does not depend on decisions I can take.
I've got to reflect a bit and decide if pursuing this idea is a good idea. Maybe I should narrow down the scope to the problem of slow diffusion in the educational system of my country... let me think about it.
Thanks,
Martin
SD Growth
Hi Martin
You have not to be the owner to model a problem.
Secondly the owners of the problem are multiple, probably
with different problems: academics, practitionners in an organisation, consultants, students and why not clients too.
This is why the problem is not so easy.
One should normally question a sample from each sub-groups to collect the problems they encounter with SD and how they would like the field to move on.
Normally it should be the work of the SD association to
make a survey perhaps every 5 years or at the most every 10 years to see how things are evoluating.
But the statistics are scarce and seem to be limited to the number of the member of the association, the number of papers at the SDC, the number of participants or the number of PHD delivered every year and I am not sure that the last is correct, maybe in the USA.
This does not show in particular how SD is concretely used on practical problems.
There is a lot that is not known at least publicly about SD, but eventually known by some.
It is like the concrete use of SD. There is the academic way that is taught and probably a more adapted way that has been developped by experience by specialized consultants but that is not taught probably because like a lot or practical field, it is vey difficult to teach it with books.
So the academic SD is roughly normalized, but the practice is probably privately hold and there is no incentive to teach it publicly. The 'private' should be interested in doing so, and should work together to build a common 'method', which is eventually impossible, because the methods depend on the
type of subjects and vary with the history of each 'private'.
Speaking about motivation, I am interested in working on a problem, to see how people deal with it, in particular with the parts that are not taught in books, and to exchange ideas about it.
There is unfortunately no place to do that.
In the business SIG, nobody seems interested.
What the administrators think about it?
I followed once a distant course supposed to teach real world modelling where I did not learn anything nor the
people attending the course with me.
This should be a good idea to develop.
Regards.
JJ
You have not to be the owner to model a problem.
Secondly the owners of the problem are multiple, probably
with different problems: academics, practitionners in an organisation, consultants, students and why not clients too.
This is why the problem is not so easy.
One should normally question a sample from each sub-groups to collect the problems they encounter with SD and how they would like the field to move on.
Normally it should be the work of the SD association to
make a survey perhaps every 5 years or at the most every 10 years to see how things are evoluating.
But the statistics are scarce and seem to be limited to the number of the member of the association, the number of papers at the SDC, the number of participants or the number of PHD delivered every year and I am not sure that the last is correct, maybe in the USA.
This does not show in particular how SD is concretely used on practical problems.
There is a lot that is not known at least publicly about SD, but eventually known by some.
It is like the concrete use of SD. There is the academic way that is taught and probably a more adapted way that has been developped by experience by specialized consultants but that is not taught probably because like a lot or practical field, it is vey difficult to teach it with books.
So the academic SD is roughly normalized, but the practice is probably privately hold and there is no incentive to teach it publicly. The 'private' should be interested in doing so, and should work together to build a common 'method', which is eventually impossible, because the methods depend on the
type of subjects and vary with the history of each 'private'.
Speaking about motivation, I am interested in working on a problem, to see how people deal with it, in particular with the parts that are not taught in books, and to exchange ideas about it.
There is unfortunately no place to do that.
In the business SIG, nobody seems interested.
What the administrators think about it?
I followed once a distant course supposed to teach real world modelling where I did not learn anything nor the
people attending the course with me.
This should be a good idea to develop.
Regards.
JJ
Hi JJ,
I tend to beleive that what we wish to see is already contained in some SD literatures. It is unlikely that the 5,000 papers included in the MIT SD DVD do not teach the concepts we want to learn.
Another approach to learning from real world examples is to read papers in other modeling fields. Apply their modeling philosophy to SD modeling.
I find many system dynamicists are to adhered to the SD technique, by thinking that dynamic problems must be solved using the SD method. Actually, some (if not all) dynamic problems can be conceptualized as static ones, and thus a spreadsheet with an Add-in Monte Carlo simulator can be used to tackle those problems in a more efficent and pragmatic fashion.
See what you think.
Monte
I tend to beleive that what we wish to see is already contained in some SD literatures. It is unlikely that the 5,000 papers included in the MIT SD DVD do not teach the concepts we want to learn.
Another approach to learning from real world examples is to read papers in other modeling fields. Apply their modeling philosophy to SD modeling.
I find many system dynamicists are to adhered to the SD technique, by thinking that dynamic problems must be solved using the SD method. Actually, some (if not all) dynamic problems can be conceptualized as static ones, and thus a spreadsheet with an Add-in Monte Carlo simulator can be used to tackle those problems in a more efficent and pragmatic fashion.
See what you think.
Monte